1. Technical Field
The inventions relate to optical communication systems.
2. Discussion of the Related Art
This section introduces aspects that may be helpful to facilitating a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
In various communication systems, an important consideration is the data transmission rate. In the context of optical communications several techniques are possible for increasing the data transmission rate. Those techniques include phase-shift keying, polarization multiplexing, and optical propagation mode multiplexing.